Toyo slider backs - what's the LF-side connection?

[ondebanks]

Here's the picture:

* I am looking to get a 4x5 camera - a Speed Graphic possibly, since I have weird lens adaptation ideas and the focal plane shutter is important for most of these.

* I'd like to use 6x9 rollfilm backs on it. All of my rollfilm backs are of the Mamiya Press S-shaped variety; I use them on a Mamiya Universal. They hold the film really flat, have a built in shutter release, safety interlocks and so on. I love them and don't want to go down the road of getting Graflok-type rollfilm backs instead.

* I am aware of Toyo "slider" backs to mount such Mamiya Press backs onto Toyo 4x5 cameras. This could be the solution I've been looking for.

So my question is straightforward: what is the type of 4x5 fitting of the Toyo backs - 4x5 Graflok, or what? What camera brands other than Toyo will they fit? Will they fit a Speed Graphic?

Thanks for any responses!
Ray

[Ralph Barker]

All of the Toyo backs with which I'm familiar have Graflok capabilities. That is to say, the "back" is two parts - a layer that interfaces to the back standard on one side and has Graflok fittings on the other; and the GG assembly that connects to the Graflok piece (not via the Graflok fittings).

Thus, you should be able to attach any Graflok-enabled film holder to the Graflok fittings on the Toyo back, but would not be able to attach the Toyo pieces to other cameras.

[Ralph Barker]

Since a photo is worth a thousand words . . .

Note that the Graflok retaining bars are beneath the spring assembly for the GG section. The interface between the entire back assembly and the rear standard is the same as the Toyo 158mm lens boards.

[ondebanks]

Since a photo is worth a thousand words . . .

The interface between the entire back assembly and the rear standard is the same as the Toyo 158mm lens boards.

Ralph,

Many thanks for your response and photos. The "interface" to the rear standard that you described is what I was asking about. It might have been clearer if I had asked the question differently, perhaps "what is the type of rear standard used in Toyo 4x5 cameras?"

Do you know if any other camera brands share the same rear standard/lens board fittings? Is the Toyo standard "standard", if you see what I mean?! As I said, I am wondering if I could fit one of these Toyo "slider" backs onto some type of Speed Graphic.

Cheers,
Ray

[Ralph Barker]

I believe the Toyo "slider" roll-film back attaches via the Graflok fittings. Thus, it is supposed to work on any camera that has a Graflok back. Note that not all Graphic cameras came equipped with a Graflok back, but the Toyo slider should work on those so equipped. Note, too, that because "Graflok" is a trademark (registered, I believe), some manufacturers refer to it as a "universal" back on their products that copy the physical interface.

[erie patsellis]

If I'm not mistaken, the back attaches (as do all the Toyo's that have removable backs) using the same size attachment as a lensboard, (158mm square, IIRC) At least all the Toyo's that I have (45E, 45F) do.

erie

[Ralph Barker]

I've not actually used or held one, Erie, so I was basing my "belief" on posts that indicate its use of the Graflok attachment, and indicating that it was originally marketed as "working on any camera with a Graflok back".

[erie patsellis]

hmm, interesting, as the one (only one, in fact) I've seen definately mounted via the standard Toyo attachment. Went for waaay too much money, hence my building a 6x7 adapter that used my RB backs with a ground glass made from a junk back. (and it rotates too!)

erie


erie

[ondebanks]

Thanks, Erie and Ralph.

I hope that we are not getting confused by the terminology. As I understand it - correct me if I'm wrong - there is the "big Graflok" or "Universal" connection for attaching 4x5 sheetfilm backs on many LF cameras, and the "small Graflok" connection for attaching 6x7, 6x9, 6x12 rollfilm backs to some MF and LF cameras. Many Speed/Crown Graphics have a "big Graflok" connection. The Mamiya RB67 and Graflex XL have a "small Graflok" connection. Right?

I think that both of you have helped to establish that the Toyo slider attaches to the rear standard of Toyo 4x5 cameras in the same way as a 158mm square lensboard. The remaining uncertainties are -

1) Is the slider a single 158mm square piece - or is there a "big Graflok" connection hiding between the 158mm board and the sliding mechanism, so that the sliding mechanism could be removed from the 158mm board and mounted on any "big Graflok" camera?

2) If it is just a single 158mm piece, then what other types of LF camera have 158mm rear standards?

Cheers,
Ray

[Ralph Barker]

I don't think there is a "Big Graflok" - although manufacturers use various slider-bar or clip mechanisms for attaching their backs to the rear standard. The Graflok or "Universal" interface is, as far as I know, designed specifically for attaching roll film backs and such to 4x5s. I don't know of any other manufacturer using the Toyo 158mm (with rounded corners) spec.

That leaves open the question of how the Toyo slider back actually attaches. A Google search on "Toyo slider back" turns up numerous references to old discussions on various forums, which may be of help.

If all else fails, you might consider making contact with Toyo directly. In the U.S. that would be through Mamiya America at 914-347-3300 or web@toyoview.com.